DPNs move fast. The 21-day clock starts from the issue date, not receipt....

https://telegra.ph/What-are-the-statutory-defences-to-a-Director-Penalty-Notice-in-Australia-05-10

DPNs move fast. The 21-day clock starts from the issue date, not receipt. Managing the lockdown vs. non-lockdown fork is critical to protecting your clients. This guide clarifies the mechanics, so you can triage fast and keep options open.